Comparative analysis of zooplankton in the Sheksna Reservoir in 1987 and 2001

Features of the structure and spatial distribution of plankton in the Sheksna Reservoir

“…However, in calm weather in the lake and near the dam in the middle of day, that difference reached 1.2-2.7°С. A big difference between the surface and bottom water temperature in summer was also mentioned earlier [16].…”

“…The shannon index of species diversity, calculated in terms of num ber, ranged between 2.93 and 3.09 in the Kovzha sec tion, 2.66 and 3.46 in the Lake Beloe section, and 1.86 and 3.69 bits in the Sheksna section. A comparable diversity of summer zooplankton (1.76-3.27 bits) was observed in the period from 1987 to 2001 [16,18]. Index values >2.5 bits on Andronikova's scale [2] cor respond to oligo and mesotrophic lakes.…”

“…The pelagic and littoral phytophilous zooplankton of the reservoir is relatively well studied [3,[14][15][16][17][18] Seventeen species were found to be most common in zooplankton of the reservoir; most of them (11 spe cies) were numerous and among dominants of the community (Table 3). In addition to those listed, Daphnia cristata Sars, Bosmina coregoni gibbera (Gosse) were among widespread (but not abundant) species.…”

“…ind./m 3 ) was recorded at a depth of >2 m in Lake Beloe and Siz'men Bay. Clusters of rotifers are possible both at the surface and at a depth of 3-5 m [3,16].…”

“…Its composition and structure are largely determined by the amount and availability of algae, which are the main trophic source for pelagic organ isms. Plankton of the Sheksna Reservoir has been studied since the reservoir was filled [3,4,11,[14][15][16][17][18]. Data collected on the expanded grid of stations char acterize the spatial distribution of phyto and zoop lankton and continue the long term monitoring of the reservoir ecosystem.…”